- Could you define 2020 vision and a few of the variants so that any person could understand it? So we think of 2020 as perfect vision. What does that mean? What would degraded vision look like? Whatever those numbers are. And then what would above normal, supra normal vision look like?

And is it true that fighter pilots have supra normal vision? - Yeah, that's another population like many athletes of people who may have sort of better than normal vision. 2020, we define almost everything we do based on kind of a average, not sick human being, adult, whatever it is, right?

And so 2020 vision means that you can read the smallest letters at 20 feet away that the average healthy person can read at 20 feet away. So you can read at 20 what they can read at 20, okay? Now, if you have worse than 2020 vision, maybe you have 2025 vision, 2040 vision, maybe you have 2200 vision, which on the eye chart at the office is like the big E at the very top is 2200 vision.

That means you can read at 20 feet what a normal person could read at 200 feet, right? So you've got pretty limited lower vision. We can measure down to like 2400, 2800. At that point, we're getting into like, gosh, can you count how many fingers I'm holding up? You know, that kind of thing.

And then ultimately hand motion, can you even tell if my hand is moving in this side of your vision or this side of your vision? And then ultimately after that light perception, can you tell if the room lights are on or off, right? And that's kind of the edge of being actually fully blind.

We call legal blindness in the United States typically 2200 or worse. - And is it true that there are people who are legally blind that are out there driving as we're having this conversation? - I have to imagine that that is unfortunately the case, but it shouldn't be because those people obviously are really severely impaired and that's obviously quite dangerous.

So that's 2020. Now it gets worse, 2040, 2080, 2100. Can it get better? Yeah, it turns out that people can be sort of on the other end of that curve. And so we could have athletes and fighter pilots or people who have had LASIK surgery who are 2015, 2010.

If you're 2010, that means you can see at 20 feet what the average person needs to be only 10 feet away to see, right? And so you've got better than normal vision. And people do get to that through a variety of ways. And so it is possible to have better than 2020 vision.

- Does the degree of visual acuity, 'cause that's really what we're talking about here, differ dramatically between the two eyes? - In most healthy people, no. Remember we talked about you're born with something like 2200 vision, takes you a couple of years and it can be a little bit asymmetric.

- 2200 vision. Yeah, that reminds me, I've seen images of what babies can see. Parents love looking at their child and thinking that their child is looking right back at them. And indeed, often the child is looking right back at them. And your face to your child, sorry to break this to you folks, is incredibly blurry, even at that close distance for probably the first six to eight months even before you come into sharp relief.

They're not seeing the fine details of your face. So smile big. - That's right, smile big. Keep those eyebrows dark. - Right, and keep cooing at them 'cause they can hear pretty well. - That's right. - Yeah, the optics of newborn babies are just dreadfully bad but they need visuals to know.

- Now other species, hawks, raptors, owls that hunt, they can naturally have 2010, 28 vision, right? So much better vision. And that's just their normal vision as best as has been measured. So there's definitely the potential for us to have better than 2020 vision. Now, all of this we call visual acuity.

And just to be clear for everyone, that's the vision in the very center of your vision. Like when you're reading or looking, that's the very center of your vision. Our vision is actually described variably as a hill of vision. The peak is in the center. That's let's say 2020 in most people, right?

But it's normal to have that slope off. And our visual acuity, your ability to read the eye chart on the edges of your vision, if you can read the big E, that's pretty normal. Like you would be 2200 out on the edges of your vision and we would feel like, yep, that's pretty normal.

So our highest acuity vision's in the center. And that's a big part of why we spend a lot of time using those eye muscles to look around, right? We gotta get a little bit of a high acuity view of what's around us, fill in the gaps of what our brain is interpreting our peripheral world to look like.

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